Vania



UNITED STATES rr'rcn.

PATENT ROBERT H. HAMILTON AND WILLIAM GRIFFITH, OF PITTSBURG, PENNSYL-VANIA, ASSIGNORS TO THEMSELVES AND CHRISTOPHER L. MAGEE AND WILLIAM A.MAGEE, OF SAME PLACE.

MANUFACTURE OF IRON.

SPECIFICATION formingpart of Letters Patent No. 226,400, dated April 13,1880.

Application filed December 13, 1879.

To all whom it may concern:

Be it known that we, ROBERT H. HAMIL- TON and WILLIAM GRIFFITH, ofPittsburg, in the county of Allegheny and State of Pennsylvania, haveinvented a new and useful In]- provement in the Manufacture of Iron; andwe do hereby declare the following to be a full, clear, and exactdescription thereof.

Our invention relates to a method of treating iron during the process ofpuddling, whereby it is more refined and rendered more tough and fibrousthan by the ordinary methods of treating iron in a puddling-furnace.

The furnace which we employ in the practical operation of our processmay be the ordinary reverberatory furnace used for puddlin g iron,although any description of reverberatory furnace adapted for boilingiron may be used. The hearth of the furnace is covered with cinder andfixed in the ordinary way, the fire is started in the grate, and thefurnace heated up as usual. The pig-iron is then charged into the hearthand the furnace fired up until the iron is completely melted. As soon asthe iron is melted the furnace is stoppered up, the damper raised, andthe fire agitated, so as to get up a strong heat, which is kept up untilthe iron has boiled from fifteen to thirty minutes. While the iron isstill boiling, and be- 0 fore it begins to come to nature, we add to thecharge of melted iron in the furnace a mixture or compound of blackoxide of man ganese, sal-soda, nitrate of soda, and muriate of ammonia.These ingredients, well mixed to- 3 5 gether in the proportionshereinafter stated, having been introduced into the hearth of thefurnace, are thoroughly stirred into the mass of melted iron, and theprocess of puddling is then proceeded with in the usual way, except- 4oing that it is unnecessary to introduce slag or cinder into the furnaceat any time during the process of puddling, and also that the iron comesto nature and can be balled and removed from the hearth much sooner thanby the or- 4 5- dinary process.

The efiect of the introduction of the mixture of ingredientshereinbefore mentioned to the melted iron before it comes to nature isthat the sulphur and other impurities in the iron and contaminations ofthe blast-furnace are 5| carried off by the slag, so that a verysuperior quality of puddled iron is produced from an inferior grade ofblast-furnace pig.

If desired, the mixture of ingredients may be added to the iron in thepuddling-furnace as 5 soon as the iron is melted and before boiling. Wedo not think, however, that this is the best method of using ourinvention, but prefer to boil the iron before introducing the physio.

We do not pretend to explain the theory on 61 which our improvement isbased, nor the chemical reactions which are produced; but we know byexperience that the muck-bar obtained after squeezing or hammering androlling the puddle-ball produced by our process, 6 even when made fromvery ordinary pig metal, is extraordinarily fibrous and tenacious, muchmore so than the best qualities of iron treated in the ordinary way.

The proportions of the ingredients which we use may be varied somewhatwithout material] y affecting the result 5 but we have found thefollowing to bea very good mixture: For a charge of four hundred andfifty pounds of pig-iron we use, black oxide of manganese, one 7 pound;sal-soda, three ounces; nitrate of soda, six ounces; muriate of ammonia,six ounces. These are to be thoroughly mixed before being used.

In place of the sal-soda, a double quantity, 8 by weight, of muriate ofsoda may be used.

Although we prefer to make use of the mixture of muriate of ammonia withblack oxide of manganese, sal-soda, and nitrate of soda, as beforestated, yet we do not wish to confine 8 our invention. to the use ofsuch mixture, as we have discovered that the muriate of ammonia may beused alone and without the other ingredients with very beneficialresults on the iron, although the result is not as satisfactory as whenthe manganese, sal-soda, and nitrate of soda are added.

If the muriate of ammonia is used alone, the quantity should be aboutdouble that before stated.

Having thus described our improvement in the treatment of iron in thepuddling process, What we claim as our invention, and desire to secureby Letters Patent, is

1. The process herein described of refining and purifying iron, whichconsists in introducin g into and mixing with the molten metal in thehearth of the furnace, and before the same has come to nature, muriateof ammonia in about the proportions and substantially as specified.

2. The method herein described of facilitating the refining process andbringing the iron to nature more quickly, which consists in com-

